.TH std::match_results::size 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::match_results::size \- std::match_results::size

.SH Synopsis
   size_type size() const noexcept;  \fI(since C++11)\fP

   Returns the number of submatches, i.e. std::distance(begin(), end()).

   Returns 0 if *this does not represent the result of a successful match.

.SH Parameters

   \fI(none)\fP

.SH Return value

   The number of submatches.

.SH Complexity

   Constant.

.SH Example


// Run this code

 #include <iostream>
 #include <regex>
 #include <string>

 int main()
 {
     std::regex re("a(a)*b");
     std::string target("aaab");
     std::smatch sm;

     std::cout << sm.size() << '\\n';

     std::regex_match(target, sm, re);
     std::cout << sm.size() << '\\n';
 }

.SH Output:

 0
 2

.SH See also

   begin  returns iterator to the beginning of the list of sub-matches
   cbegin \fI(public member function)\fP
   end    returns iterator to the end of the list of sub-matches
   cend   \fI(public member function)\fP
